Australia's Top Tourism Treasures - Shark Bay

Shark Bay, Western Australia

The wide inlet known as Shark Bay is a jewel on the Western Australian coast. Shark Bay's location in a transition zone between cold and warm ocean currents and tropical and temperate climates gives it a rich and glorious array of fauna. The sea-grass meadows here are the largest in the world and home to an estimated 10,000 dugongs, 10 percent of the world's population, and 6,000 marine turtles, including Western Australia's largest community of loggerhead turtles. Onshore, the marginal desert lands, with their sandy soils and their low, scrub-covered hills, are a refuge for endangered species, including 26 types of mammals, 13 kinds of reptiles, and three bird species.

More than 700 kinds of wildflowers grow here, and in spring their blooms blanket the usually barren soil. Moreover, alongside its many spectacular landforms, the precipitous Zuytdorp Cliffs, the wild Peron Peninsula, and Dirk Hartog Island, site of the first recorded landing of a European in Australia, Shark Bay incorporates significant geological curiosities including a beach made entirely of shells and the world's largest colony of stromatolites, Earth's earliest known life-form.

Standing on the beach is one of many ways to make contact with the dolphins of Monkey Mia. Twice daily, two catamarans set off from the town's jetty. This is not conventional cruising: the sails are unfurled and visitors perch on the edges of the deep-sea sailing vessels as they weave their way around the bay locating a wealth of marine life. Dolphins race beside the catamarans, riding the bow waves, and curious dugongs pause to investigate the disturbance as they surface for air. These magnificent creatures, sometimes known as sea pigs or sea cows and once called mermaids by sailors, are close relatives of the manatees that inhabit the Caribbean. Placid and generally timid, they can grow to a length of about 10 feet, live for 70 years, and reach a weight of 880 pounds. Sharks and orcas are their main predators, and in the past decade pods of dugongs have twice been attacked here by orcas.

From a distance, Shell Beach, 47 miles (75 km) south of Monkey Mia, appears to be just another stunning Western Australian beach: pure white, gently undulating dunes edged by calm, clear waters. But this beach is quite extraordinary: it is made entirely of millions of small, white shells. In places up to 33 feet deep, these are the shells of cardiid cockles. Like the stromatolites found farther down the coast, the cockles thrive in the high levels of salinity created by the protected, shallow bay, while their natural predators are deterred. As a result, the shells have accumulated in immense numbers over the past 4,000 years.

One intriguing result of these deposits has been the formation of a kind of shell-rich sedimentary rock, known as coquina limestone. This has become a popular building material around Shark Bay, and in the town of Denham several buildings, including a local restaurant, are built entirely out of coquina limestone blocks. The rough-hewn effect resembles pale sandstone embedded with thousands of tiny fossil shells.